Accretion Channeling in CTTSAccretion Channeling in CTTS

Scott Gregory, Moira Jardine

Classical T Tauri Stars (CTTS)Classical T Tauri Stars (CTTS)

(Goodson et al. 1997)

Magnetic Field Detection in CTTSMagnetic Field Detection in CTTS

• Surface fields of 1-3 kG detected from:

– Zeeman broadened spectral lines

(e.g. Johns-Krull et al. 1999).

– Circularly polarised lines

– Increased line equivalent widths (e.g. Guenther et al. 1999).

– Electron-cyclotron maser emission

(Smith et al. 2003).

Accreting Field ExtrapolationsAccreting Field Extrapolations

(Gregory et al. 2004, in preparation)

• LQ Hya surface

map.

• Potential field

extrapolation with

source surface.

• Isothermal corona

in hydrostatic

equilibrium.

Accreting Field ExtrapolationsAccreting Field Extrapolations

(Gregory et al. 2004, in preparation)

• AB Dor surface

map.

• Potential field

extrapolation with

source surface.

• Isothermal corona

in hydrostatic

equilibrium.

Accretion FootpointsAccretion Footpoints

Longitude

Longitude

Lat

itude

Lat

itude

LQ Hya like field. AB Dor like field.

Future Work: X-ray EmissionFuture Work: X-ray Emission

LQ Hya like field. AB Dor like field.

Future Work: X-ray EmissionFuture Work: X-ray Emission

Future WorkFuture Work

• ESPaDOnS (Echelle SpectroPolarimetric Device for the

Observation of Stars at CFHT):

– Observations of DF Tau and BP Tau (plus V410 Tau and

V830 Tau) in 2005.

(Petit, Donati & the ESPaDOnS project team 2004)

• Magnetospheric accretion models with potential field

extrapolations.